German Patent Application No. 102 01 322 574 6.5 describes a method and a control unit for controlling a vehicle braking system. To ensure a desired braking effect of at least one wheel brake of the vehicle braking system, an actuator of the vehicle braking system, in particular an electromechanical brake booster of the braking system, is to be controlled. Controlling the electromechanical brake booster should also take into account a torque loss of the electromechanical brake booster which is to be estimated for the run time, depending on the operating point.